1. Field of the Invention
The present invention relates to a touch panel and a method for operating the touch panel, and an electronic apparatus and a method for operating the electronic apparatus. In particular, the present invention is suitably applied to electronic apparatuses having a touch panel as an input device.
2. Description of the Related Art
A touch panel, also called a touch screen, is an input device with which an operator operates an apparatus by touching the screen with a finger, which has been used in various electronic apparatuses.
There are various types of touch panels, including a capacitive type, a resistive film type, an ultrasonic type, an infrared type, and an electromagnetic induction type. While touch panels of the resistive film type have been widely used before, touch panels of the capacitive type have only recently attracted attention and enable multi-point detection that would be difficult with touch panels of the resistive film type.
A touch panel of the capacitive type may have a matrix structure, as illustrated in FIG. 11. Referring to FIG. 11, the touch panel includes a base substrate, and pulse lines P1′ to Pn′ made up of n line electrodes and sense lines S1′ to Sm′ made up of m line electrodes are arranged on the base substrate. The pulse lines P1′ to Pn′ and the sense lines S1′ to Sm′ are insulated from each other and arranged so as to cross each other. The pulse lines P1′ to Pn′ are connected to a pulse generating circuit 101. The sense lines S1′ to Sm′ are each connected to a corresponding detecting circuit.
In this touch panel of the related art, as shown in FIG. 12, the pulse generating circuit 101 applies predetermined pulses (voltage) to all the pulse lines P1′ to Pn′ in turn, to carry out an “all line scan”. When the panel surface is touched with a finger 102 of the operator, a change in capacitance between one of the pulse lines P1′ to Pn′ and one of the sense lines S1′ to Sm′ is detected by the detecting circuit, whereby the touched position is detected.
Meanwhile, a touch-type input device has been proposed (see Japanese Unexamined Patent Application Publication No. 2003-84904), which includes a first sheet and a second sheet, the first sheet including a plurality of first electrodes in strip form, a first resistance component connected to the first electrodes, and first wiring connected to the first resistance component, the second sheet including a plurality of second electrodes in strip form, a second resistance component connected to the second electrodes, and second wiring connected to the second resistance component, wherein the first sheet and the second sheet are arranged such that the first electrodes and the second electrodes substantially orthogonally cross each other, and the first electrodes and the second electrodes are each divided into groups of a plurality of lines. The input device further includes a control circuit, which specifies a group of the electrodes corresponding to a touched position, and further specifies the touched position within the group. This input device, however, is considerably different from the present invention in that it fails to have first line electrodes (pulse lines) to which pulses are applied and second line electrodes (sense lines) for use in detection which are arranged to cross the first line electrodes, and in that it is not of the capacitive type.